LECTROSONICS DCHT, DCHT-E01 Instruction Manual

DCHT

Digital Transmitter

DCHT, DCHT/E01

INSTRUCTION MANUAL

Quick Start Steps

1) Install good batteries and turn power on (see pages
5 and 7).

2) Set compatibility mode to match the receiver (see
page 11).

3) Connect signal source, select input type and adjust
input gain for optimum modulation level (see page

10).

4) Set or sync frequency to match receiver (see page
11, 12). Also see receiver manual for scanning pro­cedure.

5) Set encryption key type and sync with receiver (see
page 13).

6) Set programmable switch to desired function (see
page 13).

7) Verify RF and audio signals are present at the
receiver (see receiver manual).

Fill in for your records:

Serial Number:

Purchase Date:

WARNING: Moisture, including talent’s sweat,
will damage the transmitter. Wrap the DCHT
in a plastic bag or other protection to avoid
damage.

Rio Rancho, NM, USA
www.lectrosonics.com

DCHT, DCHT/E01

Table of Contents

Quick Start Steps ................................................................ 1

Introduction ........................................................................... 3

General Technical Description ........................................... 3

DSP-controlled Input Limiter ............................................... 3

Encryption ........................................................................... 3

Features and Functions ....................................................... 4

Optional Battery Eliminator ................................................. 4

Whip Antennas .................................................................... 4

Battery Status LED Indicator .............................................. 5

Belt Clips ............................................................................. 5

IR (infrared) Port ................................................................. 5

Status LED .......................................................................... 5

Connecting the Signal Source ............................................ 5

Battery Installation ............................................................... 5

DCHT, DCHT/E01 Block Diagram ....................................... 6

Powering On and Off ............................................................ 7

Powering On in Operating Mode ......................................... 7

Powering On in Standby Mode ........................................... 7

Powering Off ....................................................................... 7

Main Menu and Setup Screen Details ................................. 7

Entering the Main Menu ...................................................... 7

Main Window Indicators ..................................................... 7

LCDMenu Map ....................................................................... 8

Input Menu .......................................................................... 10

Adjusting the Input Gain for Analog Inputs ......................... 10

Selecting the Low Frequency Roll-off ................................. 10

Selecting StMode (stereo mode) ........................................ 10

Selecting Input Type ............................................................ 10

Selecting Input Configuration .............................................. 10

Xmit Menu ............................................................................. 11

Selecting Frequency ........................................................... 11

Selecting Transmitter Output Power .................................... 11

Selecting Receiver Compatibility Mode .............................. 11

Turning Rf On/Off ................................................................ 11

Selecting M2R Receiver Functions ..................................... 12

GetFrq ................................................................................. 12

SendFrq .............................................................................. 12

GetAll .................................................................................. 12

SendAll ................................................................................ 12

Name... ................................................................................ 12

Flex ..................................................................................... 12

Key Menu ............................................................................... 13

Encryption Key Management .............................................. 13

KeyType .............................................................................. 13

MakeKey ............................................................................. 13

WipeKey .............................................................................. 13

SendKey .............................................................................. 13

Setup Menu ........................................................................... 13

Selecting AutoOn Feature ................................................... 13

Selecting Programmable Switch Functions......................... 13

Enable/Disable Remote Control Function ........................... 14

Selecting Battery Type ........................................................ 14

Locking/Unlocking Changes to Settings.............................. 14

Selecting Backlit Time ......................................................... 14

Turning LEDs Off/On ........................................................... 14

Restoring Default Settings .................................................. 14

About ..................................................................................... 14

Wireless Designer Software ............................................... 15

Firmware Update Instructions ............................................. 15

Specifications ....................................................................... 15

Input Connections ............................................................... 16

Microphone Cable Termination

for Non-Lectrosonics Microphones ............................. 17

LectroRM ............................................................................... 18

Accessories .......................................................................... 20

Troubleshooting .................................................................... 21

Service and Repair ............................................................... 22

Returning Units for Repair .................................................. 22

2

LECTROSONICS, INC.

Digital Transmitter

Introduction

The DCHT, DCHT/E01 transmitter is designed to work
with a companion receiver (such as the Lectrosonics
DCHR or M2R, part of digital camera hop systems)
as an audio relay between an audio production bag
or cart and a camera or other audio device. The 6-pin
input jack accepts two mic or line level analog signals or
AES digital signals from external sources with a variety
of adapter cables. Analog inputs can be linked for the
same gain when used with a stereo source, or operate
independently with individual settings.

This fourth generation digital design features specially
developed, high efficiency digital circuitry for extended
operating time on two AA batteries. The transmitter can
tune in 25 kHz steps across the UHF television band
from 470.100 to 607.950 MHz (E01 frequency range
is 470.100 to 614.375 MHz), with a selectable output
power of 10, 25 or 50 mW.

Studio quality audio performance is assured by high
quality components in the preamp, wide range input
gain adjustment and DSP-controlled limiting for analog
sources, and settings are included for any lavaliere
microphone, dynamic microphones, line level inputs,
and AES digital inputs. Input gain is adjustable over a
51 dB range in 1 dB steps to allow a precise match to
the input signal level, to maximize dynamic range and
signal to noise ratio.

A separate switch is provided on the top panel that can
be configured as mute, power or bypassed.

The housing is constructed of solid machined aluminum
for lasting ruggedness. The exterior is finished with an
ultra hard, dark electroless nickel finish called ebENi.

Firmware updates are made through a side panel
microB USB port.

General Technical
Description

DSP-controlled Input Limiter

For analog sources, the transmitter employs a DSP­controlled analog audio limiter prior to the analog-to­digital converter. The limiter has a range greater than
30 dB for excellent overload protection. A dual release
envelope makes the limiter acoustically transparent
while maintaining low distortion. It can be thought of as
two limiters in series, connected as a fast attack and
release limiter followed by a slow attack and release
limiter. The limiter recovers quickly from brief transients,
so that its action is hidden from the listener, but recov­ers slowly from sustained high levels to keep audio dis­tortion low and preserve short term dynamic changes in
the audio level.

Encryption

When transmitting audio, there are situations where
privacy is essential, such as during professional sport­ing events, in court rooms or private meetings. For
instances where your audio transmission needs to be
kept secure, without sacrificing audio quality, Lectro­sonics implements AES256 encryption in our digital
wireless microphone systems. High entropy encryption
keys are first created by one of the units in the system.
The key is then synced with another encryption-capable
unit, via the IR port. The audio will be encrypted and
can only be decoded if both the transmitter and receiver
have the matching encryption key. If you are trying to
transmit an audio signal and keys do not match, all that
will be heard is silence.

Canada ISED Notice

This device operates on a no-protection, no-interference basis. Should the user seek to obtain
protection from other radio services operating in the same TV bands, a radio licence is required.
For further details, consult Innovation, Science and Economic Development Canada’s document
Client Procedures Circular CPC-2-1-28, Voluntary Licensing of Licence-Exempt_Low-Power

Radio Apparatus in the TV bands.

Rio Rancho, NM

3

DCHT, DCHT/E01

Features and Functions

Battery

status LED

Enter menu/Select item

Return to

previous screen

Status Ready LED

Menu navigation

USB Port

Power

Programmable

function switch

Audio

input

jack

Bi-directional IR port

Modulation

indicators*

Antenna

port

Optional Battery Eliminator

The transmitter can be powered by external DC using
the optional LTBATELIM power supply adapter. The
battery door is replaced by the adapter with a simple
procedure. The adapter provides a locking coaxial con­nector and a variety of power cords and connectors are
available.

Whip Antennas

Because the transmitter tunes across such a
broad frequency range, it is best to use the ap­propriate antenna for maximum operation. Two
antennas are included with the transmitter, and
are shipped from the factory pre-cut and fully
assembled. Each antenna covers three blocks.
Refer to the chart below to determine which an­tenna matches the operating frequency you will
be using.

Frequency Cap
Block Range MHz Color Antenna

470 470.100 - 495.600 Black AMM19

19 486.400 - 511.900 Black AMM19

20 512.000 - 537.500 Black AMM19

21 537.600 - 563.100 Red AMM22

22 563.200 - 588.700 Red AMM22

23 588.800 - 607.950 Red AMM22

4

LECTROSONICS, INC.

Digital Transmitter

Battery Status LED Indicator

The Power/Function LED on the top panel will mirror
the keypad LED unless the programmable switch is set
to Mute, and the switch is turned on.

Alkaline, lithium or rechargeable batteries can be used
to power the transmitter. The type of batteries in use are
selectable in a menu on the LCD.

When alkaline or lithium batteries are being used, the
LED labeled BATT on the keypad glows green when the
batteries are good. The color changes to red at a mid­point of the runtime. When the LED begins to blink red,
there will be only a few minutes of operation remaining.

The exact point at which the LEDs turn red will vary
with battery brand and condition, temperature and
power consumption. The LEDs are intended to simply
catch your attention, not to be an exact indicator of
remaining time.

A weak battery will sometimes cause the Power LED to
glow green immediately after the transmitter is turned
on, but it will soon discharge to the point where it will
turn red or the unit will turn off completely.

Rechargeable batteries give little or no warning when
they are depleted. If you wish to use these batteries
in the transmitter, the most accurate way to determine
runtime status is by testing the time provided by a par­ticular battery brand and type, then using the BatTime
function to determine remaining runtime.

NOTE: Refer to the Main Menu and Setup section
for BatTime details.

Belt Clips

The wire belt clip may be removed by pulling the ends
out of the holes in the sides of the case. Be sure to
have a firm grip to avoid scratching the surface of the
housing.

An optional spring-loaded, hinged belt clip (model num­ber BCSLEBN) is also available. This clip is attached by
removing the plastic hole cap on the back of the hous­ing and mounting the clip with the supplied screw.

IR (infrared) Port

The IR port is available on the top of the transmitter for
quick setup using a receiver with this function available.
IR Sync will transfer the settings for frequency from the
receiver to the transmitter.

Status LED

Blue LED indicates ready (transmitting) status.

Connecting the Signal Source

Microphones, line level audio and digital sources can be
used with the transmitter. Refer to the section entitled
Input Connections for details on the correct wiring for
line level sources and microphones to take full advan­tage of the Servo Bias circuitry.

Battery Installation

The transmitter is powered by two AA batteries. Lithium

batteries are recommended for longest life.

The battery status circuitry compensates for the differ-

ence in voltage drop between alkaline and lithium bat-

teries across their usable life, so it’s important to select

the correct battery type in the menu.

Because rechargeable batteries run down quite abrupt-

ly, using the Power LED to verify battery status will not

be reliable. However, it is possible to track battery status

using the battery timer function available in the receiver.

Push outward on the battery compartment door and lift

it to open.

Slide door outward,

then lift up to open

Insert the batteries according to the markings on the

back of the housing.

If the batteries are inserted incorrectly, the door may

close but the unit will not operate.

The battery contacts can be cleaned with alcohol and

a cotton swab, or a clean pencil eraser. Be sure not

to leave any remnants of the cotton swab or eraser

crumbs inside the compartment.

Spring contacts

Rio Rancho, NM

5

DCHT, DCHT/E01

Input

DCHT, DCHT/E01 Block Diagram

CHANNEL 1

Input

Preamp

Shunt

Limiter

Servo Bias

Supply

Gain

Adj

Bias Voltage

0, 2 or 3.6V

HI/Lo

Pass

Filter

Limiter Control

Converter

Audio

I2S

A-D

Jack

123456

Rate

Converter

CHANNEL 2 (analog/digital selectable)

Shunt

Limiter

Input

Preamp

Servo Bias

Supply

Gain

Adj

Limiter Control

Bias Voltage

0, 2 or 3.6V

HI/Lo

Pass

Filter

Audio

A-D

Converter

I2S

DSP Clock

Oscillator

VCTCXO

36.864 MHz

Status Ready

PLL Ref

Phase Locked Loop

Microprocessor

Keypad

D-A Converter

I2S

Control

Baseband

Firmware

Update

Voltage Controlled

Oscillator

I + Q

Signals

(2) AA

Batteries

UART

Switching

Power

LED

Tricolor

IR Port

Power

Supply

Low
Pass
Filter

Low
pass

lters

USB

Jack

IQ Modulator

Buer

Final

Amplier

Filters

6

LECTROSONICS, INC.

Powering On and Off

Digital Transmitter

power button.

Powering On in Operating Mode

Press and hold the Power Button for a few seconds
until the progress bar on the LCD finishes.

When you release the button, the unit will be operation­al with the RF output turned on and the Main Window
displayed. You can also use the programming switch if it
is configured for this function.

Hold
for
Rf On

DCHT

MUTE

470.100

-40

-20

+0

Powering On in Standby Mode

A brief press of the power button , and releasing it
before the progress bar finishes, will turn the unit on
with the RF output turned off. In this Standby Mode the
menus can be browsed to make settings and adjust­ments without the risk of interfering with other wireless
systems nearby.

RF indicator blinks

Hold
for
Rf On

NOTE: After settings and adjustments are made,
press the power button again to turn the unit off or
navigate to menu item Xmit, RFOn? to choose to
begin transmitting.

Release

Power Button
before the bar
progresses to
enter Standby

Mode

DCHT

470.100

-40

-20

+0

Main Menu and Setup
Screen Details

Entering the Main Menu

The LCD and keypad interface makes it easy to browse
the menus and make the selections for the setup you
need. When the unit is powered up in either the oper­ating or the standby mode, press MENU/SEL on the
keypad to enter a menu structure on the LCD. Use the

and arrow buttons to select the menu item. Then

press the MENU/SEL button to enter the setup screen.

Input...

Gain

Rolloff
StMode

The prompt in the upper right corner may

display one or both arrows, depending upon

what adjustment can be made. If the changes

are locked, a small padlock symbol will appear.

Main Window Indicators

The Main Window displays the current settings, status,
audio level and battery status.

Programmable

Switch Function

Frequency (MHz)

DCHT

MUTE

470.100

-40

-20

Gain

-40

Battery status

+0

25

-20

0

Operating

mode

(Transmit or

Standby)

Powering Off

To turn the unit off, press and hold

Powering

O...

the top panel switch is turned back on again before the
progress bar finishes, the unit will remain turned on and
the LCD will return to the same screen or menu that
was displayed previously.

NOTE: If the programmable switch is in the OFF
position, power can still be turned on with the

Rio Rancho, NM

hold the Power Button for a few
seconds and wait for the progress
bar to finish, or use the program­mable switch (if it is configured for
this function).

If the power button is released, or

Audio level

If the programmable switch function is set for MUTE,
the Main Window will indicate that the function is en­abled.

Mute function

enabled but

not active

DCHT

MUTE

470.100

-40

-20

+0

When the switch is turned on, the mute icon appear­ance will change and the word MUTE will blink at the
bottom of the display. The -10 LED on the top panel will
also glow solid red.

Mute function

enabled and active

DCHT

MUTE

470.100

Main Window will

blink the word

MUTE when the

audio is muted

<–MUTE–>

7

DCHT, DCHT/E01

Use arrow buttons

SEL button to

LCD
Menu Map

Settings will be stored
when the BACK button

is pressed.

Input...

Xmit...

SEL

BACK

SEL

BACK

Gain

1

22

20

Rolloff

StMode

InType

InpCfg1

InpCfg2

Freq.

470.675

Grp 1

Gain

2

SEL

SEL

SEL

SEL

SEL

select channel
(gain value
highlighted)

Rolloff

1

BACK

Hz Hz

StMode

Indep.

BACK

Linked

InType

Analog

BACK

AES

InpCfg1

Line In

BACK

InpCfg2

Oth Lav

BACK

70 70

2

1

2

Select value with arrow buttons

to select value

22 20

Level meter at bottom of screen

Select option with arrow buttons

Select option with arrow buttons

Select setting with arrow
buttons: PSA, DPA, B6,
COS-11, MKE 2, M152, Oth
Lav, Custom, Line In, Dynamic

Select setting with arrow
buttons: PSA, DPA, B6,
COS-11, MKE 2, M152, Oth
Lav, Custom, Line In, Dynamic

Press MENU/SEL to highlight MHz or kHz or to
select a Frequency Group

Select value with arrow buttons

NOTE: When StMode is set
to Linked, a single gain value
field will be shown

Compat

IR&Key

SEL

SEL

BACK

BACK

Txpower

Rf On?

Compat

Duet
DCHX

SendFrq

SendAll

GetFrq

GetAll

BACK

BACK

TxPower

10 mW
25 mW
50 mW

Rf On?

Yes
No

Select option with arrow buttons

Select option with arrow buttons

SEL

SEL

Select option with arrow buttons

BACK

BACK

BACK

BACK

SendFreq

Sync

SendAll

Sync

GetFreq.

Sync

GetAll

Sync

Press UP arrow button to begin sync

Press UP arrow button to begin sync

Press UP arrow button to begin sync

Press UP arrow button to begin sync

SEL

SEL

SEL

SEL

KeyType

SEL

KeyType

BACK

8

Select option with arrow buttons:
Shared, Standard, Volatile,
Universal

Shared

LECTROSONICS, INC.